DE60318885T2 - BRAIDED STENT AND METHOD FOR THE PRODUCTION THEREOF - Google Patents

Abstract

A stent includes regions of differing numbers of braided filaments to provide different dimensions and/or properties in different regions along the stent length. The stent may include a first and second plurality of braided filaments each braided together. The second plurality of braided filaments is braided into the first plurality of braided filaments to form a region of different properties than the first. A method of constructing a braided stent includes the steps of braiding a first plurality of filaments to form the flexible portion, combining a second plurality of filaments to the first plurality of filaments, and then braiding the second plurality of filaments with the first plurality of filaments to form the more rigid region from the combination of the first and second plurality of filaments, where the second plurality of filaments is braided only in the rigid region.

Description

TECHNICAL AREA

These This invention relates generally to stents and stent grafts and more particularly to braided stents and stent-grafts with segments with different strength and rigidity along the length and / or different diameters with variable or constant strength and stiffness along the length.

BACKGROUND OF THE INVENTION

One Stent is an elongated device that is used to support a Cavity wall is used. A stent creates along with a graft cover or fairing an unobstructed channel for fluid flow in the Area of a stenosis. Such a stent graft would typically have a tubular graft layer cover or lining, with the interior or exterior of the stent (or both) thus creating a fluid channel to a stenosis or otherwise Diseased body passage to get around.

Various types of stent architectures are known in the art, including many constructions with a filament or a number of filaments, such as filaments. As a wire or wires that are wound or braided to a special configuration. Among these wire stent configurations, braided stents are included, such as: In the U.S. Patent No. 4,655,771 , Hans I. Wallsten, is described. The Wallsten patent is but one example of the many variations of braided stents known in the art and, thus, is not intended to be a limitation on the invention described hereinafter. Braided stents are usually very pliable, having the ability to be placed in a tortuous anatomy and still maintain patency. The pliability of braided stents makes them particularly well-suited for use in delivery within a lumen when the lumen of the vessel becomes twisted and irregular both before and after placement of the stent.

The most common Use of stents and stent grafts is in the vascular system, in the stents and stent grafts with a first compressed Small diameter configuration in a body cavity at one of a location In this cavity remote point can be introduced needs a repair and then through this cavity, typically through a catheter can be transported to this point. Once the body, the a repair is needed If the stent or stent graft is in a second, expanded Configuration either expanded or expanded to one to create an open passage through this place.

Lots However, these braided stents have the problem that they either are too rigid, so the delivery and arrangement within cavity becomes difficult or too flexible (at the expense of Reduction of radial strength), so that radial expansion forces, the at the treatment site are inadequate to open one To maintain passage through the place adequately. By Increase Moreover, the radial strength of a stent typically becomes flexibility decreased because the stent is more rigid. Likewise, by increasing the Flexibility often sacrificed the radial strength.

consequently There is still a need for a fully supported stent graft create that for the navigation through winding cavities is flexible enough, though is rigid enough to properly anchor the device and the continuity through the device at the treatment site.

WO 03/057079 A1 that form part of the subject under Article 54 (3) EPC describes a tubular stent that can be inserted into the body 16 with discrete tubular segments in an alternating sequence of segments 22 with high axial rigidity and segments 24 with low axial stiffness. Around the segments 22 . 24 With different axial stiffness, the stent can 16 either by simply wrapping and interlacing several elastic biocompatible strands 28 whereby a pitch is changed at least once during winding to form portions of different axial stiffness, or by arranging the wound string 28 on a thermosetting mandrel 34 with several mandrel segments 38 . 40 be formed with different diameters. When deployed in a body cavity, the stent extends 16 to a predetermined diameter, ie the diameter of the deployed stent 16 is constant. This is best done by comparing 5 and 6 see where the same stent 34 in a form before implantation ( 5 ) showing sections of different diameter, and in the implanted situation ( 6 ), in which the diameter of the stent 34 is equal over its entire length, is shown. A stent as defined in the preamble of claim 1 is in EP 0 897 698 A2 disclosed. The stent of this document has different mesh patterns. The stent generally has a tubular shape and functions to support a portion of a body cavity from the interior thereof. When delivered, the stent may be in the shape of a football, thus damaging the wall of the hollow space through which it must be transported and in which it is unfolded. Once deployed, the stent has the same diameter along its entire length.

SUMMARY OF THE INVENTION

The The present invention provides a stent having segments with different ones Diameters with variable or constant properties along its length. In an unclaimed embodiment the diameter is constant along the length of the stent, but the stiffness of the stent changes along the longitudinal axis. In one embodiment the stiffness of the stent remains the same along the longitudinal length but the diameter changes yourself. In another embodiment, change both the stiffness and the diameter along the length of the Stents. This variance in diameter or in radial strength or stiffness is due to the use of different numbers of filaments braided to the stent at different Achieved jobs. If more rigidity or the same rigidity with a larger diameter he wishes In general, more filaments are added.

The The invention comprises a stent with a narrow area and a wider area, with the wider area comprising more filaments Than the narrow area, so that increased radial strength in the wider Area is shown. The stent of the present invention has a first plurality of filaments extending over the whole narrow area and the wider region, and a second plurality of Filaments that extend along only the wider area. The second plurality of filaments is in the first plurality of filaments woven. In a preferred embodiment, the stent comprises also a transition area between the narrow area and the wider area. The transition area consists of the first plurality of filaments, their braid in the Diameter increases from the narrow area to the wider area.

In The invention also provides a method for braiding a stent an area with relatively greater flexibility and a relatively higher range included radial strength. The method comprises the steps first braiding a first plurality of filaments around the to form more flexible area, and then adding one second plurality of filaments to the first plurality and the braiding the combination to form the stiffer area of the stent. The Method preferably comprises the steps of first braiding a first plurality of filaments around a narrow area then combining a second plurality of filaments with the first section and the braiding of the second plurality filaments with the first plurality of filaments around one wider range from the combination of the first and the second plurality to form filaments. The method preferably comprises the Lichen the stent around a spine with a spine body that consists of a first section and a second section, wherein the first step is braiding the first plurality of filaments around the first spine section and the last step is the braiding the second plurality of filaments in combination with the first Comprises a plurality of filaments around the second mandrel portion. The second plurality of filaments is present only in the more rigid region. The second mandrel portion preferably has a larger diameter on as the first mandrel section.

One optional but preferred feature of the invention is the creation an atraumatic closure on the braided stent structure both at the stent ends and at the middle stent sites, where a plurality of braided filaments ends.

BRIEF DESCRIPTION OF THE DRAWINGS

The Invention is best understood from the following detailed description, when read in conjunction with the accompanying drawings becomes. It is emphasized that according to the usual Practice some of the features of the drawings are not to scale. In contrast, the dimensions of some of the features of the clarity half arbitrary enlarged or reduced. In the drawing, the following figures are included:

1A is a side view of a non-stressed stent with a constant radius;

1B Figure 11 is a side view of a stent according to the present invention having a narrow area and a wider area;

2 is a partial close-up view of a portion of the stent of 1A or 1B between the bendable area and the rigid area;

3 FIG. 10 is a side view of a mandrel used in accordance with the present invention to replace that in FIG 1B to produce the stent shown;

4 Fig. 3 is a front view of a part of a braiding machine used to braid the narrow area of the braiding machine 1B shown stents is used;

5 Figure 3 is a front view of a portion of a braiding machine used to braid the wider area of the braiding machine 1B shown stents used becomes;

6 is a side view of a portion of a braiding machine used to braid the in 1B shown stents is used; and

7 Figure 5 is a partial close-up view of an atraumatic end of a stent according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The Invention will be next explained with reference to the FIG. in which in all figures similar numbers specify the same elements. Such figures are intended to illustrate rather than limit and are included here to explain the device of the present To facilitate invention.

Regarding 1A is an unstressed braided stent 10 shown. For the purposes of this invention, a braided stent is one formed from at least two sets of parallel continuous filaments, with the two sets passing the perimeter of the stent in longitudinal but angularly intersecting directions. The two sets of filaments are interlaced or intertwined to form a support structure. The in 1A Stent shown comprises a relatively flexible area 11 and a relatively rigid area 12 (with a greater radial strength than the flexible region 11 ). The rigid area 12 includes more filaments than the flexible region and therefore has greater radial strength. In an unclaimed embodiment (and as in 1A shown) is the number of filaments in the rigid region 12 twice that of the bendable area 11 , A stent, as in 1A can be braided on a mandrel (not shown) using the method described in detail below.

With reference now to 1B is a braided stent 100 shown in accordance with the present invention. As in 1B As shown, the stent comprises a narrow area 110 (or smaller diameter) defining a first cavity and consisting of a first plurality of filaments and a wider area 120 (or larger diameter), which defines a larger cavity than the first cavity. The wider area 120 consists of the majority of filaments from the narrow area 110 plus a second plurality of filaments braided into the first plurality of filaments. The narrow area 110 has a greater flexibility than the wider area 120 and also points to the wider area 120 a greater radial strength than the narrow range 110 ,

1B also shows a transition area 130 , The transition area is between the narrow area 110 and the wider area 120 formed and consists of the filaments that make up the narrow area 110 form. The transition area 130 is formed during braiding on a mandrel with a varying diameter, as described in more detail below.

In the 1A and 1B stents shown are uniform stents. That is, the stent is in one piece in contrast to modular stent designs where two or more stent segments are joined together to form the various parts of the entire device (eg, a block section and two legs). Thus, a unitary stent contemplates a stent whose entire length is manufactured as a single unit without the need to secure additional stent segments in deployment. The stent, as in 1B For example, although shown to be uniform, it has various radial strengths along its longitudinal axis. This is due to the introduction of additional filaments in the wider range 120 ,

It should be noted here that the unitary stent 100 , as in 1B is just one exemplary embodiment and that this invention is equally applicable to "modular" braided stents. As used herein, the term "modular" means a stent having at least two discrete sections configured for in-situ assembly. As is well known in the art, one type of exemplary modular stent may comprise a modular branched stent having a block portion with a branched portion terminating in two short sleeves into which two discrete leg members are adapted for insertion. Although not shown herein, such general configurations are well known in the art. Thus, while the invention primarily refers to a non-branched structure as illustrated and described herein, each of the methods and structures described herein are equally applicable to pieces of structures such as e.g. Block components for accommodating modular leg members which may themselves be made in accordance with the present invention.

The braiding of the filaments forming the stent of the present invention may be performed on a braider having a predetermined plurality of reel carriers configured to rotate in a pattern about a longitudinal axis. A first set of reel carriers may be configured to rotate in a first circumferential direction, and a second set of reel carriers may be configured to rotate in a second circumferential direction, each one of which Reel carrier is designed to carry at least one reel. Each reel is designed to provide one or more filaments for braiding the stent.

In Such a case involves braiding the narrow or flexible one Range the use of filaments from a first section the predetermined plurality of reels around the narrow portion to braid the first, narrow section of the detachable mandrel leg, essentially along the longitudinal axis in a braiding zone is arranged. The braiding zone is defined as a conical zone, which is defined by the filaments extending from the reels extend to the stent on the spine. The preferred number of to Lathing of the narrow area filaments used is 12, though Any suitable number may be used to achieve the desired balance between compressibility and radial strength of this range. The at the present Filaments used in the invention may be any, those skilled in the art are known and can preferably a wire such as. Nitinol or stainless steel or can comprise a polymer.

At the Lichen of the wider or stiffer area includes the process The addition of filaments from a second portion of the predetermined plurality from reels to the number of filaments used to braid the wider area around the second portion of the detachable mandrel leg used, which is arranged in the braiding zone to increase. The added additional Filaments are used in conjunction with those already in place Filaments used by braiding the narrow area of the stent. In other words, this second step involves the use filaments of both portions of the predetermined plurality from reels to the body around the second mandrel body with a larger diameter to braid, which is arranged in the braiding zone. The second plurality Of filaments is only in the wider area and nowhere else used in the stent.

2 shows a flattened, partial view of the lower part of the wider area 120 who in 1 is shown. This part of the stent according to the present invention will be discussed in more detail below. At each overlap, one filament is disposed radially outward relative to the other filament. For example, following each filament along its helical path through a series of successive overlaps, this filament may lie in an overlap in the radially inner position and in a next overlap in the radially outer position or may be in the inner position for two overlaps and in the outer Position for the next two, and so on. As mentioned above, exemplary braided stents are in the U.S. Patent No. 4,655,771 , Hans I. Wallsten, revealed. A typical braided stent is placed on a mandrel by a braiding or folding machine such. For example, a standard braiding machine known in the art and manufactured by Rotek of Ormond Beach, Florida is formed. However, any such braiding or folding machine may be used and the use of terminology specific to components of the machine manufactured by Rotek is not intended to be a limitation on the use of this machine design. To the extent that the terminology used herein is specific to the components of any one or more machines, it should be understood that those components specifically referred to herein generally have corresponding functionally equivalent components with respect to other machines , Thus, the scope of the method of braiding the stent of the present invention described and claimed herein is not intended to be limited to the particular machine embodiment described herein, but also extends to functionally equivalent machines.

Braiding machines may be used to manufacture the stent of the present invention around an exemplary modular mandrel, as in U.S. Pat 3 shown to be used. In 3 includes the thorn 300 a lower area 310 and an upper area 320 , being a transitional area 330 is arranged in between. These areas correspond to the narrow area, the wider area or the transition area, as in 1B shown. pencils 340 are also shown. The pencils 340 are used to anchor filaments during braiding, an aspect known to those skilled in the art, which will be discussed in more detail below.

With reference now to 4 and 5 is a braiding machine 70 schematically as typically with a number of notching wheels 72 shown in a circle. In the 4 and 5 shown machine 70 has twenty such scoring wheels 72 each notch wheel being adapted to rotate in the opposite direction to its adjacent nother wheels, as indicated by arrows A and B. This opposite rotation guides the reel carrier 71 and the attached reels 74 in a sinusoidal manner from wheel to wheel, thus causing the reels to rotate about a longitudinal axis on which the circle is centered. The configuration of the notch wheels, the reel beams, and the reels to accomplish this movement is well known in the art, and an example of such a configuration can be found in the braiding machine manufactured by Rotek.

Each reel comprises a filament wound thereon 75 , The capstan and reel typically interface in a manner that helps maintain the wire unwinding from the reel under proper tension, as known in the art. Although the movement of the reels is described herein, it should be understood that the reels 74 be moved by them on reel carriers 71 are attached. Although empty reel carrier 71 in 4 Thus, each reel is shown (as darkened circles without filament extending therefrom) 74 Also attached to a reel carrier, which produces a "loaded" reel carrier. To the disorder in 4 and 5 to reduce, is the underlying reel carrier for with reels 74 loaded carriers not shown.

During braiding, the spine becomes the braided stent 100 is formed, such. B. the thorn 300 , as in 3 shown moving in a controlled manner substantially along a longitudinal axis, around which the circle of the scoring wheels 72 centered and around which the reel carrier 71 rotate. 6 represents such a configuration from the side. Consequently, the wires extend 75 while braiding from the braiding machine 70 to the thorn 300 in a conical configuration, like in 6 shown.

How out 6 As can be seen, when two reels intersect, their respective filaments form an overlap, leaving the filament from the reel at the outer radius 76 radially outward (relative to the axis of the assembled stent) relative to the filament of the reel at the inner radius 78 is arranged. The space contained within the cone formed by the wires extending between the reels and the mandrel and including the space occupied by the mandrel is referred to herein as a "braiding zone". 90 designated. Although the angles α ₁ and α _{2 of} the wire to the mandrel may be changed as desired, α ₁ and α ₂ preferably each include an angle of approximately 55 ° when the braid angle of a braided stent β is approximately 110 °. This angle may vary depending on the exact radial position of the reel relative to the mandrel and whether the wire is in an overlap in the inner radial position or outer radial position. As used herein, the term "substantially along the longitudinal axis" as used with respect to the orientation of the moving mandrel means that the mandrel does not have to be perfectly centered in the braiding zone, but only needs to be aligned sufficiently close to the longitudinal axis, so that the angles of the filaments between the mandrel and the reels enable the braiding process to create a functional braid without entangling the filaments.

To form a braid around a thorn, the wires can 75 extending from the reels 74 extend, be attached to the end of the spine in almost any way, such. By wrapping or binding them, and in particular need not be kept in any particular orientation. For example, all wires may be wound or bonded to a single point on one side of the mandrel. Once the braiding machine starts, it stabilizes to the proper braid configuration after only a few peripheral rings of overlaps are formed. The portion between the convenient configuration and the end may either be cut away as waste or unbundled and then manipulated to form a non-braided finish as discussed below herein. Alternatively, to minimize the waste, the ends of the wires 75 wrapped around pins or otherwise on the mandrel in a spaced circumferential configuration similar to the configuration of reels 74 in the braiding machine 70 be attached.

In a preferred embodiment becomes each of the two halves from each filament wrapped around a separate reel, leaving the filament Filament on two reels, each half of the filament on one separate reel, is wound. In such a case, a first end of the filament wound on a first respective reel and a second end of the filament becomes a second respective one Reel wound, with the filament midpoint between the two Reels are exposed. From this pair of reels becomes the center pulled out of the filament and arranged on the mandrel to a point at a point where each filament is added to the stent. It is not necessary for the exact midpoint between the two reels is uncovered, except that the filament is generally equivalent Wrapped on each reel, leaving enough of the filament on each Reel exists to facilitate braiding of the stent.

For example, if a stent such. B. the in 1B As shown, six pairs of reels are prepared and placed on a braiding machine as described in more detail below. Every tip 140 for a total of 6 tips is formed by attaching the approximate center of each Fila element on the mandrel. When 12 reels are arranged to provide 12 wires for braiding (a "wire" extending in opposite directions from each of six points) 140 extends) becomes the narrow area 110 braided. In such a case, although six filaments are actually used, the narrow portion is effectively braided with 12 wires because each filament is at the tip 140 bends. Once the narrow area 110 and the transition area 130 are then braided, then additional six pairs of Reels added, with six tips 150 at the beginning of the wider area 120 be formed. Consequently, the wider area becomes 120 as shown, braided effectively from 24 wires. The tips described above are preferably formed by winding each filament around a respective pin on the mandrel, as is well known in the art. Each such pin is the point where a point is formed.

In such a case, as just described, the first and second bobbins should be placed on reel carriers in positions consistent with the screw angle of the stent and the distance of the mandrel from the bobbin carriers. Thus, depending on the exact configuration of the machine and the desired helix angle of the stent, the first and second reels may be disposed at opposite ends of a radius of a circle of score wheels or at opposite ends of any chord through the circle. An exemplary process for creating a stent with such ends is in the publication WO 99/25271 , Burlakov et al.

In a method for producing the braided stent of the present invention, the braiding machine is first as shown in FIG 4 shown with a first section 73 a predetermined number of reels 74 stocked. The predetermined number of reels may include the maximum capacity of the machine. In such a case, another machine with at least twice the number of reel carriers would have to be used to braid the wider area. Alternatively, the first section 73 comprise half of the reel capacity of the machine. This latter embodiment is the one described in 4 in which 10 of the 20 available reel carriers are loaded and ready for braiding.

The braiding operation is then performed, as described above, around the narrow portion of the braided stent around the lower portion 310 of the thorn 300 to build. After braiding the narrow area around the lower portion of the spine and the transition area of the stent about the transition area of the spine, the stent is ready to add the additional filaments so that the additional filaments can bond to the existing filaments and, together, the wider one Area 120 around the upper area 320 of the spine.

When to weave the narrow area 110 As described in more detail below, the existing filaments used to complete the braiding must be secured to prevent play or loosening of this already braided portion of the stent. This can be done either by setting each one on a pin to the mandrel or simply binding or clamping all the filaments to the mandrel at a point where the additional filaments are added to form the wider area of the stent.

As As stated above, the method of adding Filaments to prepare for braiding the wider area moving the ones used in braiding the narrow area Coiling reels. This movement can be through any one of Number of ways performed become. Certain reel carriers can for example, closed eyelets include, through which the wire is threaded, in which case the whole reel carrier can be removed. Other reel carriers, such. For example, for example, from the Wardwell Braiding Machine Company in Central If RI is made, open, crimped guides, which resemble a "pig's tail", so the reels simply unlocked and lifted from their respective reel carriers can be and the filament can be easily removed from the guide. It should be self-evident be that, as stated herein, removing or replacing "the Reels "on the and removing or replacing only the reels from the machine or the reels that are still attached to the reel carriers include can. If the whole reel carrier can be removed, the reel carrier be removed by simply removing any fastening devices, which keep him in place, be removed to a faster one Removal and replacement may be facilitated by a quick connect fitting be used. The quick connect fitting may be any Number of means well known in the art for providing comprise a locking engagement of one element with the other, such as B. a magnetic connection, a twisting and locking connection, a compound of a spring-loaded ball in a channel, a lever-controlled cam connection or any in the art known compound.

The filament addition process can be performed essentially by comparing 4 and 5 be understood. Before adding the filaments, the reels are as in 5 shown, with pairs of reels are arranged relative to each other, which are shown with empty reel holders between each pair. In order to prepare for braiding the wider area of the stent, in one embodiment additional reel pairs are added between each reel pair used to braid the narrow area.

If the coiler used to brace the narrow area of the stent does not have any additional bobbin holders (a situation that occurs in 4 not shown), the reel pair and mandrel system used to brace the narrow region and transition region can be moved to a machine having at least twice the number of reel carriers. During the reel movement step in such a case, it is desirable to rotate each reel 74 to keep clockwise or counterclockwise. It can be said that the reel carriers 71 form a first set of reel carriers that make up the circle of kerf wheels 72 in the counterclockwise direction, whereas reel carriers 71 form a second set of reel carriers that traverse the circle in the clockwise direction. Further, when the entire bobbin carrier is removed, it is desirable that the bobbin carrier be exchanged in a position in which it runs in the same direction as it had run before removal.

Important in the filament adding step is that the reels are arranged either by moving to another machine or by adding additional reels to obtain the desired overlap between the filaments. For example and as in 2 The general pattern over the entire length of the filament is shown below / above / below / above. In certain areas such. B. for the filament 210 in the transition area 130 However, the filament such. B. the filament 210 to successive parallel filaments 211 and 212 arranged underneath. The preferred arrangement of the braid may vary and is generally known to those skilled in the art. As long as a desired pattern is known, the reels can be arranged as the wider area filaments are added to achieve this desired pattern.

With regard to again 4 and 5 The counter rotation of the scoring wheels means that every notch wheel 72 with a clockwise rotating reel 74 at the outer radius 76 adjacent notch wheels on both sides with the clockwise rotating reel at the inner radius 78 having. In an alternative embodiment, the reel carrier 71 (and therefore the reels 74 ) run clockwise instead of counterclockwise, with the carrier 71 and reels 74 run counterclockwise. However, it may be preferred that the tangent of the wire to the reel is on the same side of the reel as it is on the mandrel so that the wire is wound in the same helical direction on the mandrel as it was wound on the reel. As in 4 For example, the wire shown by the reel is shown 74 springs, tangential to the right side of both the reel and the spine 300 and so is the wire coming from the reel 74 springs, tangential to the left side of both the reel and the spine.

In order to provide increased radial strength at the ends of the braided stents of this invention, or to counteract a known end effect of a braided stent architecture in which the ends usually have lower radial strength than the central portion of the stent, the ends may be flared, as shown in FIG known in the art, or the ends may comprise a non-braided stent architecture, as in 7 is shown. The structure and method of making a hexagonal non-braided architecture 700 with an overlapping end winding 710 , in the 7 can be accomplished by known winding and welding methods. In the in 7 embodiment shown is each filament end 710 to an adjacent filament piece near its end 710 welded. sharpen 720 are formed to make the end of the stent atraumatic. Shorter filament segments under the tips 720 may end in another way, such as B. by shearing the same at the otherwise closed free ends 730 , The final architecture, as in 7 can be described as "atraumatic" in the sense that there are no loose or pointed wire ends that can pierce or irritate the cavity wall after implantation (or otherwise cause trauma to it). Other methods of providing atraumatic ends may also be used, as known in the art. The end architecture is not limited to the architecture shown and described above, but may include any number of configurations known in the art.

Atraumatic ends of the braided stent structure may also be created by making adjacent filament pairs of filaments of each of the angled sets of parallel filaments continuous with each other. Such atraumatic ends may be at the end of the stent, as in 140 in 1B to see, or at the middle stent end of a stent area, as in 150 in 1B to see where an additional plurality of braided filaments are continuous with each other.

Moreover, using the method described above, one end of the stent has atraumatic tips 140 made of continuous wire, such as. In 1B at the end of the narrow area 110 shown. The filaments at the opposite end are preferably also atraumatically arranged ends in a non-braided architecture, such as those in FIG 7 ge showed tips 720 , However, these are only examples, as the free ends may terminate in any manner known in the art. Although one end of a stent has a certain combination of tips 720 made of continuous wire and otherwise free ends 730 The preferred embodiment includes one end of the stent with only tips 720 made of continuous wire.

Around To develop the stent of this invention, the stent typically becomes in a radially compressed state in an insertion device compressed as is well known in the art. The stent will then inserted into the cavity, in which it is to be deployed, through the cavity to a deployment point navigates, typically a diseased artery such. The aorta, and then at the deployment site in a radially expanded state expanded as known in the art. The unfolding of a uniform stent of the present invention is therefore characterized by a procedure performed similar to that is that for any stent known in the art is used. The Expansion is also achieved by known methods (eg the stent between the radially compressed configuration and the radially expanded configuration expandable by one of: Balloon expansion, self-expansion via spring elasticity or self-expansion via a heat or stress-related return a preconditioned shape memory material).

Even though non-branched stent constructions are shown and described herein For example, the method of the present invention may be used to generate Stent segments are used, which are combined to branched Systems or any number of multiple cavity systems form.

Of the Stent of the present invention may also be used with any biocompatible Graft associated with it as one of: an outer cover, an inner lining or a combination thereof. These grafts are known to professionals. As used herein, the term "stent" is generally intended to refer to a wire support frame alone or a wire support frame in conjunction with a graft material containing it is connected as one of: an outer cover, an inner Disguise or a combination thereof. This latter stent will sometimes called a "stent graft" or "prosthesis that out a stent and a graft ".

Even though above with reference to embodiments described with only two areas with different properties, Be stents or stent grafts with three or more areas with different characteristics also considered and can too by duplicating the above teaching for the introduction and conclusion of a separate plurality of filaments produced at a middle stent site become.

It It should also be noted that the various properties that by changing the number of filaments provided in a braided stent structure not on a customized or stiffness / flexibility / strength properties are limited, but may include other properties, such as. B. magnetizability, Imaging capability, Volume density (the ratio filament-occupied or unoccupied stent circumference), etc.

Even though with reference to certain specific embodiments Although illustrated and described, the invention is not intended to be the details shown to be limited. Rather, different modifications can be made be made to the details within the scope.

Claims (26)

Tubular stent comprising at least one area ( 11 ; 110 ) in the longitudinal direction extending from a second area ( 12 ; 120 ) of the stent with respect to the diameter and / or mechanical properties, wherein the stent is characterized by: a first plurality of braided filaments ( 211 . 212 ) extending through the stent defining a non-branched tubular stent having a single longitudinal axis, the plurality comprising two sets of parallel filaments arranged at an angle relative to each other defining the perimeter of the stent over its entire longitudinal length and in the longitudinal direction thereof run; and a second plurality of braided filaments ( 200 ), which only cover a second area ( 12 . 120 ) extend in the longitudinal direction, wherein the second plurality of filaments ( 200 ) in the first plurality of braided filaments ( 11 ; 110 ) only along the second area ( 12 ; 120 ), wherein the one longitudinal region ( 11 ; 110 ) has a diameter which is smaller than the diameter of the second longitudinal region ( 12 ; 120 ). Stent according to claim 1, further comprising a transition region ( 130 ) between the one longitudinal region ( 11 ; 110 ) and the second area ( 12 ; 120 ), the transition region ( 130 ) the first plurality of filaments ( 211 . 212 ) contains. The stent of claim 1 combined with a biocompatible tubular graft, wherein the graft comprises one of the following elements: an outer cover, an inner lining or a combination thereof at least for one section ( 11 ; 110 . 12 ; 120 . 130 ) of the stent. The stent of claim 1, wherein the filaments are wire include. The stent of claim 4, wherein the wire is either nitinol or stainless steel is. The stent of claim 1, wherein the stent extends between two ends and each end has an atraumatic termination structure (Fig. 710 . 720 . 730 ) having. The stent of claim 1, wherein the stent is a radial compressed configuration for the introduction in the cavity and a radially expanded configuration for deployment in the cavity has. The stent of claim 7, wherein the stent is between the radially compressed configuration and the radially expanded configuration is expandable by one of the following elements: balloon expansion, self expansion by spring elasticity or self-expansion by heat or claim-related return a preconditioned shape memory material. The stent of claim 1 comprising a narrow portion and a wider portion, the second plurality of braided filaments ( 200 ) only along the wider area ( 120 ). Stent according to claim 9, wherein the transition region ( 130 ) the first plurality of braided filaments ( 211 . 212 ) whose diameter is of the narrow range ( 110 ) to the broader area ( 120 ) increases. A stent according to claim 9, which is biocompatible tubular graft combined, the graft being one of the following elements includes: an outer cover, an inner panel or a combination thereof at least on a section of the stent. The stent of claim 9, wherein the filaments are wire include. The stent of claim 12, wherein the wire is either Nitinol or stainless steel is. The stent of claim 9, wherein the stent extends between a narrow end and a wider end and each filament at the wider end in an atraumatic termination structure (US Pat. 710 . 720 . 730 ) ends. The stent of claim 9, wherein the stent extends between a narrow end and a wider end and each filament at both ends in an atraumatic closure structure ( 710 . 720 . 730 ) ends. The stent of claim 9, wherein the stent is a radial compressed configuration for the introduction in the cavity and a radially expanded configuration for deployment in the cavity. The stent of claim 16, wherein the stent is between the radially compressed configuration and the radially expanded one Configuration is expandable by one of the following elements: Balloon expansion, self-expansion by spring elasticity or self-expansion by heat or claim-related return a preconditioned shape memory material. A method of constructing a braided stent according to claim 1, comprising a first and a second region (Fig. 11 . 12 ) in the longitudinal direction with different properties, said method comprising the steps of: (a) braiding a first plurality of filaments ( 211 . 212 ) comprising two groups of parallel filaments around the first longitudinal region ( 11 . 12 ) to build; and (b) braiding the second plurality of filaments ( 200 ) with the first plurality of filaments ( 211 . 212 ) to the second longitudinal section ( 12 ) to build; wherein the second plurality of filaments ( 200 ) only in the second section ( 12 ) is braided and the first plurality of filaments ( 211 . 212 ) in the longitudinal direction over the entire length ( 110 . 120 ) of the stent. The method of claim 18, which comprises performing braiding on a braiding machine ( 70 ), which a predetermined plurality of reels ( 74 ), which are designed to rotate about a first longitudinal axis, comprising a first group of reels ( 74 ) is adapted to rotate in a first circumferential direction, and a second group of reels ( 74 ) is adapted to rotate in a second circumferential direction, each reel ( 74 ) on a reel carrier ( 71 ) adapted to receive at least one reel ( 74 ), each reel ( 74 ) to provide one or more filaments for braiding to the stent; wherein step (a) comprises the use of filaments from a first portion of the predetermined plurality of reels ( 74 ) for braiding the one longitudinal area ( 11 . 12 ) around the first mandrel portion disposed substantially along the longitudinal axis in a braiding zone, the braiding zone being a conical zone defined by the filaments elements ( 211 . 212 ) defined by the reels ( 74 ) to the stent on the spine ( 300 ) and wherein step (b) involves the use of filaments from both fractions ( 11 . 12 ) of the predetermined plurality of reels ( 74 ) for braiding the second longitudinal section ( 12 ) around the second mandrel portion positioned in the braiding zone. The method of claim 19, further comprising the steps of: (A) first performing step (a); (B) then removing the first portion of the predetermined plurality of reels ( 74 ) from the braiding machine ( 70 ) and removing the spine ( 300 ) from the braiding zone; (C) then performing step (b); (D) then returning the first portion of the predetermined plurality of reels ( 74 ) in the braiding machine ( 70 ), Fixing the spine ( 300 ) on the mandrel body and positioning the mandrel ( 300 ) in the braiding zone; and (E) then performing step (c). The method of claim 20, further comprising the steps of: before step (a), winding each filament ( 211 . 212 ) between two reels ( 74 ), such that a first end of each filament ( 211 . 212 ) on a corresponding reel ( 74 ) and a second end of each filament ( 211 . 212 ) to a second corresponding reel ( 74 ) and positioning a point of each filament ( 211 . 212 ) on the thorn ( 300 ) to form a point at a point where each filament ( 211 . 212 ) is added to the stent. The method of claim 19 for constructing a braided stent that covers a narrow area (Fig. 110 ) and a wider range ( 120 ), which has a larger diameter than the narrow area ( 110 ), the method comprising the following steps: (a) braiding a first plurality of filaments ( 211 . 212 ) to form the narrow area; (b) combining the second plurality of filaments ( 200 ) with the narrow region formed in step (a) ( 110 ); and (c) braiding the second plurality of filaments ( 200 ) with the first plurality of filaments ( 211 . 212 ) to the wider area ( 120 ) from the combination of the first and the second plurality of filaments ( 200 ; 211 . 212 ) to build; wherein the second plurality of filaments ( 200 ) only in the broader area ( 120 ) is braided. The method of claim 22, including braiding the stent about a mandrel ( 300 ) having a mandrel body comprising a first portion and a second portion, wherein step (a) comprises braiding the first plurality of filaments ( 211 . 212 ) around the first mandrel section and step (c) comprises braiding the second plurality of filaments ( 200 ) associated with the first plurality of filaments ( 211 . 212 ) is combined to the second mandrel portion. The method of claim 22, which comprises performing braiding on a braiding machine ( 70 ) comprising a predetermined plurality of reels ( 74 ) designed to rotate about a longitudinal axis, wherein a first group of reels ( 74 ) is adapted to rotate in a first circumferential direction, and a second group of reels ( 74 ) is adapted to rotate in a second circumferential direction, each reel ( 74 ) on a reel carrier ( 71 ) adapted to receive at least one reel ( 74 ), each reel ( 74 ) is adapted to provide one or more filaments to braid them into a stent, wherein step (a) comprises the use of filaments from a first portion of the predetermined plurality of reels (US Pat. 74 ) for braiding the narrow area ( 110 ) around the first mandrel section positioned substantially along the longitudinal axis in a braiding zone, the braiding zone being a conical zone defined by the filaments extending from the reels (Fig. 74 ) to the stent on the mandrel, and wherein step (b) involves the use of filaments from both portions of the predetermined plurality of reels (US Pat. 74 ) for braiding the wider area ( 120 ) around the second mandrel section positioned in the braiding zone. The method of claim 22, further comprising the steps of: (A) first performing step (a); (B) then removing the first portion of the predetermined plurality of reels ( 74 ) from the braiding machine ( 70 ) and removing the spine ( 300 ) from the braiding zone; (C) then performing step (b); (D) then returning the first portion of the predetermined plurality of reels ( 74 ) in the braiding machine ( 70 ), Fixing the spine ( 300 ) on the mandrel body and positioning the mandrel ( 300 ) in the braiding zone; and (E) then performing step (c). The method of claim 22, further comprising the steps of: before step (a), winding each filament between two reels ( 74 ), such that a first end of each filament is supported on a first corresponding reel ( 74 ) and a second end of each filament is wound onto a second corresponding reel ( 74 ) and positioning a point of each filament on the Thorn ( 300 ) to form a point at a location where each filament is added to the stent.